Tube bender



c. N. MATTHEWS TUBE BENDER June 10, 1930.

2 Sheets-Sheet 1 Filed Dec. 27, 1928 A TTOR NE YS.

June 10. 1930. c. N. MATTHEWS TUBE BENDER 2 Sheets-Sheet 2 Filed Dec.27. 1928 v INVENTOR.

. Char/es A! l'fazkh ems BY 77W 77- a ATTORNEYS.

Patented June l O, 1930 NI ED S A oHA eL smMArrHnws, or Los AivenLns;camromvr i i Application filed December 27,1928. Serial at. 328,750.

g This invention relates to a bending machine designed to bend bars,tubes and the llke in a curve. Heretofore; it has been common practiceto provide-a curved former 5 having-a grooved seat for a tube or bar, a

lever pivotally mounted and carrying a bending roller. The tube or. barto be bent is clamped in position againstthe former between it and thebending-roller and the 10 lever swung to bend the bar or tube againstthe seat. This requires considerable force to be exerted to swing thelever, Furthermore, each machine has' been limited to onev slze of baror tube and one radius of curvature for the bend. H

The objects of this invention are to pro-' vide a bending machineqhaving' power amplification means to cause travel of the bending rollerover the'bar or. tube. seat; to bending machine having a former hableand:

providea and roller arranged to. be'detac interchangeable .with .otherformers and rollers to accommodatethe machine to diflen;

invention illustrated in the accompanying.

drawings, in which I, I

Fig. 1 is a plan view of 'a' complete sembly, the upper cover plate ofthe ratchet handle being removed to betterillustrate the ratchetstructure; Fig. 2 is a front view as seen looking in the direction ofthe arrow 2 in Fig. 1; Fig. in thedirection of the arrow 3 in Fig. 1;Fig. 4 is a-view similar-to Fig. 3 showing another size of former-anditsqcoacting roller, parts being shown inc-section to better illustratethe 'invention; Fig. 5 -.is a section as seen on the line 5 5 ofFig; 1;and Fig.

6 is afragmentary section in plan showing the reversible ratchet.

Referringwith more particularily to the drawings, A indicates asemi-circularbase plate arranged with suitable bolt holesl nd 3--is arear ;view looking serving tor attaching thebase "pljate to'a bench ortable in horizontal position. The base plate has bolted thereto asemi-circular rack B whichcomprises a segmental gear." Detachablyboltedto the rack B is'a former markedC in Figs. ,1, 2, 3 and 5 and c in- 4.Pivotally secured to'the former is a lever v indicated generally by D.Journalled on the;

lever is a bending roller to coact-with the former seat marked E inFigsl 2 and'3 ande. in Fig.- 4. A

having astubshaft to receive, a ratchet han-J dle G. 1 I

v The base plate A corresponds 'in fcurvature. to' the rack. It hasv aflat-lower face" 10 so as to lie flush againstsurface to isa hub portion11', and

the table or ,bench' :be'bolted. There qwhich it-may; I

;a rim; portion '12- with an intermediate cut-awayqportion 18. The uppersurface; of the rim and hub are in alinement. 1

the heads bench. A

Bolt holes with-sockets for of bolts to be sunk therein are baseplate inposition upon a peripheral1-recess15 serves as a track for a roller asis later described,

' Rack B joined by. holes I regi has a hubtportionl6 and a rim 17 web18. Inthe web are bolt stering with corresponding bolt Gear 'teeth'areprovided on-the periphery of the rim; On.

recess 20 serving as a track for a roller. the rack in former C; Figs.1-, 2, 21 a'nd a r the 1under face of the rim 1s a "is shown bolted to l3 and 5 .;,;This former has a hub im 22fjoined by a web-2'3. Bosses orprojections; are provided adjacent, the

rim as indicated by and sockets for; the.

the former to the rackfth'ere bemg ing alined tapped bolt former c shownin 24 which have bolt holes heads of bolts25 secur holes the rack. TheFig. 'is of like construction; but smaller in curvature and there arebolt holes withthe respects, former 0 is as to dlmensions.

former is in the. rack which will register the former 0 In. other likeformer C except In the periphery of the a semi-circular, groove 26serving oltholes in bolts 14 mounted therein for V V .base to receive.bolts 19 for sewise secured to shaft 38 is a pinion 39 mesh- 7 as a seatfor the tube to be bent. An opening is provided in the hub 21 concentricwith the periphery of the rack B for receiving a bolt 27 serving as aspindle for the bending lever D.

Referring particularly to Figs. 1, 2 and 3, the lever D comprises an arm28 mounted uponspindle 27. Secured to the end of the arm 28 is a crossmember 29 having a guide track 30 for the ratchet handle Gr. Bolted tothe under side of the rail 30 is an L shape arm 31, there being a brace32 to add to the stability. J ournalled upon a trunnion extending fromthe end of arm 31 is a roller '33 riding in way 15 of the base plate. A

roller 34 is journalled on a spindle mounted on top of arm 31 andtravels in way 20. Slidably mounted upon arm 28 is a block 35 carryingrollers 36 which rideupon the upper surface of the former. Block 35 isadjustable as to position so that it may be accommodated to theparticular former used, it being held in adjusted position by set screws37. J ournalled in arms 28 and 31 is a shaft 38 having a squared end38to receive ratchet handle G. Keyed or othering with the teeth on rack B.Obviously, by turning the pinion, the lever A will be caused to swing.

To prevent retrograde movement of the lever, a pawl mechanism isprovided consisting of a bushing 40 upon which is rotatably mounted aring 41. Ring 41 has diametrically opposed cars 42* and 42 and a lug 43.Pawls 44* and 44 are pivotally mounted upon the arm 31, being secured tothe corresponding ears 42 and 42 by links 45* and 45" which slidablypass through holes in the ears, the links being provided with abutmentheads. Compression springs 46 and 46 embrace the links and act betweenthe ears and pawls. The construction is such that the ring 41 may bepositioned so as to .ma'intain one pawl in engagement with the teeth onthe rack and the other pawl retracted as shown in Fig. 6 or thepositions of the pawls may be reversed by turning the ring. Turning ofthe ring is accomplished by means of a connecting link 47 secured to lug43 at one end and at the other end to a pin on a disk 48. Disk 48 has aspindle journalled in arm 31 to which a wing 49 is afiixed so that byturning the disk, the pawl mechanism may be disposed to prevent movementof the lever either in one direction or the other.

The ratchet handle comprises a handle portion 50 with a head 51 in whichis journalled a ratchet wheel 52. The ratchet wheel 52 has asquareopening to detachabl-y receive the end .38 of the pinion shaft. A pawl53 is provided for engaging the teeth 9 the ratchet wheel and a manuallyoperable post 54 provides for releasing the pawl from the ratchet. Theparticular details of the ratchet handle forms no part of the presentinvention and may be varied in its details.

In Figs. 1, 2 and 3 a bending roller E is shown journalled upon shaft38, there being a suflicient space between the grooves in the bendingroller and in the former to accommodate ,a tube. If a smaller former isused as shown in Fig. 4, the lever is demounted and a bar 55 bolted toarm '31. Bar 55 carries a roller 56 which rides upon the upper face ofthe rack. Suitable holes are provided in the arm 28 and correspondingholes in the bar 55 for receiving a shaft 57 upon which is journalledbending roller 6 to cooperate with the former 0. Obviously, varioussizes of formers may be used and bending rollers will be correspondinglymounted between arm 28 and bar 55.

In order to clamp the bar or pipe in position upon the former a clampcomprising jaws 58 and 58 is secured by pins 59 and 59 to the former atthe rear. Provision is made for securing the clamp at either side of'theformer so that bending may be performed from either end. A correspondingclamp for the smaller former is shown in Fig. 4.

In order to bend a pipe or bar, the latter is inserted 'in the clansipopening and between the bending roller and the former. The ratchethandle is then oscillated, the reversible pawl having been positioned-toprevent retrograde movement. Oscillation of the ratchet handle causesrotation of the pinion and travel of the latter arounduthe rack. Thiscauses the lever to be swung and with it the bending roller so that thetube is pressed against the grooved seat in the former and bent to thedesired shape.

What I claim is:

1. A bending machine comprising a peripherally curved rack, said rackhaving an undercut way, a former detachably see cured to said rackincluding a peripherially arcuate tube seat concentric with said rack, abending lever pivotally and detachably secured to said rack and formerat the center of their arcs, said lever including ,a yoke arm havingrollers journalled thereon and riding in said way, a pinion journalledon said lever and meshing with said rack, means to rotate said pinion tocause said lever to turn, and a bending roller journalled on said leverto coact with said seat.

2. A bending machine comprising a pcripherally arcuate rack, said rackhaving an undercut way, a former detachably secured to said rack andincluding a peripherially arcuate tube seat concentric with said former,a bending lever pivotally and detachably secured to said rack and formerat the center of their arcs, said leverincluding i'is a yoke arm havingrollers journalled thereon $550 and riding in said way, a pinionjournall'ed on said lever and meshing with said rack,

means to rotate said pinion to cause said lever to turn, a pawl mountedon said lever and engaging the teeth of said rack toprevent retrogrademovement of said lever, and a bending roller journalled on said lever tocoact with said seat.

3. A bending machine comprising a peripherally arcuate rack, a formerdetachably secured to said rack and including a peripherally arcuatetube seat concentric with said rack, a bending lever pivotally anddetachably secured to said rack and former at the center of their arcs,a bending roller journalled on said lever to traverse said seat andcoact therewith, a pinion journalled on said lever and meshing with saidrack, said rack having an undercut way, said lever including ayoke armhaving rollers journalled thereon and riding in said Way, said pinionhaving a shaft provided with a stub end, a ratchet handle on said stubend to rotate said pinion and turn said lever, and

a reversible pawl mechanism mounted on said leverand engaging the teethof said rack to prevent retrograde movement of said lever.

In witness that I claim the foregoing I have hereunto subscribed mynamethis 15th day of December, 1928. p N. MATTHEWS.

CHARLES

